The inevitable turned into the unavoidable on Wednesday when the New Orleans Saints placed offensive left tackle Willie Roaf on injured reserve, thus ending his season, and signed free agent lineman Scott Sanderson to replace him on the roster.

	Roaf

On Tuesday, Roaf, 31, underwent surgery to repair the torn anterior cruciate ligement in his right knee and to mend some cartilage damage as well. The seven-time Pro Bowl performer will need 6-8 months to rehabilitate.

"It's a big loss for us," said Saints coach Jim Haslett. "He's such a great player and hopefully a future Hall of Famer. It will be hard to replace a guy like that."

Sanderson, 27, signed a two-year contract, returning to the game after being released by the Cleveland Browns this summer.

A four-year veteran, Sanderson has played both guard and tackle in his career, appearing in 32 games and starting six of them. He entered the league as a third-round selection of the Houston Oilers in 1997 and then moved with the franchise to Tennessee. He was an unrestricted free agent this summer, spent much of his time working out with the Titans and hoping to be re-signed by the club, but was not.

He signed with Cleveland when Browns tackle Tony Jones retired just one day into camp but was released during the preseason.

The former Washington State star recently auditioned for the expansion Houston Texans, who are permitted to beginning signing so-called "street" free agents next month, and had a solid workout. Sanderson started three contests at left tackle in 1988 and three at left guard in 1999 before suffering a ruptured disk in his back. He played in eight games for the Titans last season.

Despite some suggestions that Roaf might retire, including one by Haslett, his representatives have said he plans to return in 2002. Roaf is due a bonus of $6.5 million next spring.

A nine-year veteran, and one of the most celebrated left tackles of the past decade, Roaf missed two games earlier this season with a different knee injury. In an Oct. 11 contest against Atlanta, he bruised the meniscus and also a bone in the right knee. He recovered through non-surgical rehabilitation and returned to the lineup on Nov. 11. He began to have additional problems with his knee, however, a week ago and that precipitated the Wednesday surgery.

The Saints had expressed hope that Roaf's operation would only involve removal of a piece of the medial meniscus, one of the cartilage pads between the upper and lower bones of the knee.

Had that been the only procedure, Roaf would have missed only two weeks, Haslett said.

"We anticipate his return to action next year stronger based on the surgery that was performed today," general manager Randy Mueller said. "Throughout his rehabilitation, we expect Willie to remain a big part of the team as we move forward this year."

Third-year offensive lineman Daryl Terrell, who has replaced Roaf in four games this season, will start at left tackle.

"I believe that Daryl Terrell has done a more than adequate job the last three games," Haslett said. "I think he gets better every game he plays."

Len Pasquarelli is a senior writer for ESPN.com. Information from The Associated Press was used in this report.